Pill
There are several types of pill, taken by mouth, that prevent pregnancy. The pill contains hormones that disrupt the ovulation of the egg in women, makes the lining of the womb thin and unsuitable for implantation of an embryo and thickens the mucus in the cervix so the sperm find it hard to swim into the womb. Therefore the pill will prevent a pregnancy occurring or implanting. The most common type is the combined pill, which contains two hormones, oestrogen and progesterone; these are the same hormones that are produced by the ovaries. There are many different types of combined pill, some of which have higher or lower hormone doses than others. If you do not get on with one brand of pill, your doctor can change to a different one. If taken properly, the combined pill is over 99% effective but it can become ineffective if a pill is missed, or if you are ill and so the pill cannot be absorbed properly by your body (for example if you have diarrhoea or vomiting). The pill does not interrupt sex (unlike condoms), is effective at regulating periods, improvingheavy and painful periods, and can help acne. Some women’s health disorders (such as endometriosis, which causes very painful periods) are treated using the pill. The pill is taken for 21 days in a row, followed by a 7 day gap, during which you will have a period (also known as a withdrawal bleed). If you miss a period during this time, you should take a pregnancy test. Side effects usually improve with time, and most commonly include mood changes, breast tenderness, nausea, and headaches. Breakthrough bleeding and spotting is common when first starting the pill, but if it persists you should see your doctor. If you have a severe headache with a change in your vision, chest pain or shortness of breath or leg pain after starting the pill, you should stop it immediately and seek medical help.
The progesterone only pill only contains progesterone and needs to be taken at the same time each day to be effective. It is used for women who cannot take oestrogen and women over 35 who smoke. It is over 99% effective but it can fail if it is taken late. The side effects are similar to the combined pill, but irregular spotting, breakthrough bleeding and irregular periods are much more common, especially in the beginning. After a few months most women find that this improves, and some stop having periods altogether (but they return on stopping the progesterone only pill).
Oral contraceptives do not provide any protection against sexually transmitted infection, and you should use condoms in addition at the start of any new relationship.